1. Field of the Invention
The present invention relates to an image forming apparatus for image recording according to image information obtained for example by reading an original document.
2. Description of the Prior Art
As an example of such image forming apparatus, there is already known so-called facsimile apparatus for image recording by a printer in response to image information transmitted from a distant place through a public telephone line. The conventional facsimile apparatus is however associated with a low resolving power limited to the order of 8 or 7.7 lines/mm and with a low image processing speed, so that an improvement in the resolving power and the processing speed would be desirable.
Also, in the case of transmitting image information read on an image reading unit simultaneously to plural printers, it is difficult to synchronize the recording operations of such printers with the image reading operation for example of a solid-state imaging device in the image reading unit, since said recording operations have different timings from unit to unit.
It is therefore proposed to temporarily store the image information of one page or several pages in a memory, and to read said information thus stored in synchronization with the horizontal synchronizing signal for each printer unit.
Such memory will however require a rather large capacity, for example on the order of 32 Mbits in the case of recording an A3-sized original with a resolving power of 16 dots/mm, and will therefore be expensive.
Also, in the case of real-time recording of the image information from the image reading unit, the synchronization between the reading unit and the printer unit is often disrupted due to ambient conditions or time-dependent changes, and such disrupted synchronization is a cause of deterioration in the image quality.